CREATE TOPIC

The CREATE TOPIC call creates a topic.

When creating a topic, you can add topic consumers to it and topic settings.

CREATE TOPIC topic_path (
    CONSUMER consumer1,
    CONSUMER consumer2 WITH (setting1 = value1)
) WITH (
    topic_setting2 = value2
);

All the parameters except the topic name are optional. By default, a topic is created without consumers. All
the omitted settings are also set by default (both for the topic and its consumers).

Examples

Creating a topic without consumers with default settings:

CREATE TOPIC `my_topic`;

Creating a topic with a single consumer and the important option enabled:

CREATE TOPIC `my_topic` (
    CONSUMER my_consumer WITH (important = true)
);

Full list of available topic consumer settings

• important: Defines an important consumer. No data will be deleted from the topic until all the important consumers read them. Value type: boolean, default value: false.
• read_from: Sets up the message write time starting from which the consumer will receive data. Data written before this time will not be read. Value type: Datetime OR Timestamp OR integer (unix-timestamp in the numeric format). Default value: now.

Creating a topic with the retention period of one day:

CREATE TOPIC `my_topic` WITH(
    retention_period = Interval('P1D')
);

Full list of available topic settings

• min_active_partitions: Minimum number of topic partitions. During automatic load balancing, the number of active partitions will not decrease below this value. Value type: integer, default value: 1.
• partition_count_limit: Maximum number of active partitions in the topic. 0 is interpreted as unlimited. Value type: integer, default value: 0.
• retention_period: Data retention period in the topic. Value type: Interval, default value: 18h.
• retention_storage_mb: Limit on the maximum disk space occupied by the topic data. When this value is exceeded, the older data is cleared, like under a retention policy. 0 is interpreted as unlimited. Value type: integer, default value: 0
• partition_write_speed_bytes_per_second: Maximum allowed write speed per partition. If a write speed for a given partition exceeds this value, the write speed will be capped. Value type: integer, default value: 2097152 (2MB).
• partition_write_burst_bytes: Write quota allocated for write bursts. When set to zero, the actual write_burst value is equalled to the quota value (this allows write bursts of up to one second). Value type: integer, default value: 0.
• metering_mode: Resource metering mode (RESERVED_CAPACITY - based on the allocated resources or REQUEST_UNITS - based on actual usage). This option applies to topics in serverless databases. Value type: String.